Mussel Rock is a rock formation on the coast of San Mateo County, California, offshore from Daly City. It consists of one large and numerous smaller rocks of a type known as a stack, where a headland is eroded unevenly, leaving small islands. The rock itself is located 15 meters from the shore of Mussel Rock Park and stands 18 meters tall. The coastal area adjacent to the rock is Mussel Rock Park, consisting of 250 acres of land stretching along the coastline. The park includes a beach area, a paragliding launch pad, hiking trails, and a parking lot.